<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="myCanvas" width="300" height="200"></canvas>
<script type="text/javascript">
var ctx = document.getElementById('myCanvas').getContext('2d');
for (var i = 0; i < 12; i++){
	ctx.strokeStyle="red";
	ctx.lineWidth = 1+i;
	ctx.beginPath();
	ctx.moveTo(5,5+i*14);
	ctx.lineTo(140,5+i*14);
	ctx.stroke();
}
</script>
</body>
</html>  
